Some ElectronicsTools

Reading Digital Calipers With an Arduino / USB



Potential applications:
 • Log measurements during production QC, alarm for low supply material stack height.
 • Large display or audible reading for visually impaired (go/no-go measurement tones)
 • NC Mill style machine position reading on a jig doing repetitive operation.

Links:
  Reading Digital Calipers With an Arduino USB   
(http://www.instructables.com/id/Reading-Digital-Callipers-with-an-Arduino-USB/)

Great reference on reading digital calipers
   
arduinotronics.blogspot.com   harbor-freight-pittsburgh-calipes

"Little Machine Shop" in Pasadena might be a useful source of desktop machinery.
They have a connector (make for a scale) that plugs into the calipers.

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 SMD Hot Air Rework Station and Soldering Iron  $69.99  
  An example an inexpensive surface mount circuit board repair station with hot air de-soldering, these can also be used to assemble some PCB designs more easily then a suzy bake oven. Solder paste applied through a mask may stick the parts down, to help prevent the air from blowing away components.





A handy Guide: Tools and Techniques for Hot Air Soldering Surface-Mount Components 


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 Low cost Logic Analyzer

 There are a number of instruments these days made more inexpensive than traditional ones by reducing them to dongle size packages making use of the resources in a PC to do much of the work.




AZDelivery Logic Analyzer USB 24M 8CH 24MHz  $8.99 at Amazon

8 Channels, 24 Mhz sample rate (<<= 12 Mhs signal bandwidth)

Should be great for looking at things like PWM outputs driving an LED,  a little sketchy for monitoring tricking timing on interfaces on a 12 Mhz clock microprocessor, it can completely miss some pulses on a 1 Ghz ARM processor.

There are many Chinese suppliers of this generic box that plugs into our PC USB connector

It uses ribbon connector pin jumpers shat should plug right into GPIO connections on an Arduino


( Our friend who managed a school project that was run on the space station used a couple of these analyzers instead of poking bare wires into the BNC connectors of donated oscilloscopes)



--- More professional Instruments  (a quick review turned up) ---



 USB Logic 100MHz 16Ch Logic Analyzer for ARM FPGA $69.99 (Amazon)

An upgrade of the box with jumper wires approach
Specs are really thin on this listing, one would assume it has 100 Mhz bandwidth.




 Hantek LA5034 PC USB Logic Analyzer 34CH 150MHz 500MSa/s Sample Rate  $99.99
 
 Accessories include 0.1" wide clips, essential if directly examininglot of chip leads





--- Self Contained Digital Occiloscopes --- 



 Open Source 2.4" TFT 1Msps with Probe and Protective Case

Nyquist Theorem suggests that the roughest approximation of a signal requires a sample rate double the signal frequency, so at best this thing can display a 500khz analog signal (a sinewave would look a rectangle wave with some phase distortion, the old audio CD standard uses a 44khz sample rate to get a 20Khz bandwidth) 50Khz signals would be displayed with a better approximation of the original waveform.

I got one like this on Ebay, it turned out to be a clone of the jyetechDSO138, using pirated firmware and artful copies of their printed guide (assembled scope was $15.45, case $4.71) takes some time to fit it to multiple layers of acrylic.

Down to $10.99 for scope without case here.

It uses a STM32F103Cx processor which delivers exceptional benchmarks results for the price.

Mine was quite noisy, one fix is to relocate the signal input and reference voltage of the chip to a common PCB point.  Replacing their negative supply voltage switching circuit with a purpose built IC (ICL7660) should also lower the noise.







A nicer looking package with slightly better specs: 12bit, 5mV/div to 20V/div sensitivity range.
                                                                                  Bandwidth: 0 - 200KHz 
External power supply not included.





 There are higher bandwidth/Price scope modules out there, but you can get a real scope from the long time authority, Tektronix starting at $415

2 channel scopes  (Amazon listing shows the same case and approximate same weight for all these)
30 Mhz    $415
50 Mhz    $479
70 Mhz    $818
100 Mhz  $1,124  (their old base model 100mhz CRT scopes with no storage were about $1500)
150 Mhz  $1,416
200 Mhz  $1,702



---  Digital Occiloscopes Dongles --- 

PicoScope 2204A $139.00  (Amazon)
  • 2 channel 10 MHz, 8-bit oscilloscope with BNC connector probes
  • 10 MHz bandwidth
  • 100 MS/s sampling
  • Advanced digital triggers
  • Arbitrary waveform generator
 The Amazon listing data is a bit confused, this is one of a 5 model product line, the top end model has 200 mhz bandwidth using 1 GS/sample rate.
 
PicoScope2200ASeriesDataSheet.pdf


Pico 2205A PicoScope 2 channel , 25MHz, 200MS/s sample rate , Includes probes  $225

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